1. Field of the Invention
The present invention relates to a heat exchanger, and more particularly, to a heat exchanger adapted for use as a condenser, an evaporator or the like employed in the car air conditioners or room air conditioners.
2. Prior Art
Heat exchangers of the so-called multi-flow or parallel flow types are widely used for example as the condensers in the car air conditioners. Each heat exchanger of such types generally comprises a body which is composed of flat tubes arranged parallel at regular intervals and a pair of left-hand and right-hand hollow headers. The headers are disposed close to ends of the tubes which are connected to the headers in fluid communication. It has been a common practice to connect an inlet pipe for supplying the body with a heat exchanging medium to one of the headers, with an outlet pipe for discharging the medium being connected to the other header. Joints of the so-called flared connection type have been secured to the ends of such an inlet and outlet pipes.
Thus, the inlet and outlet pipes for charging or discharging the medium have independently been connected to the respective headers, so that a space large enough to receive the heat exchanger inclusive of the pipes must be provided in an automobile body or the like object. Therefore, the heat exchanger body must be designed considerably small. In addition, the inlet and outlet pipes must be arranged in the automobile body in such a state that other adjacent devices or the like thereon would not interfere with said pipes. This often has undesirably resulted in a complicated, for example repeatedly bent, configuration of those pipes.
It also has been a problem that the joints of flared connection type, which are attached to the ends of the inlet and outlet pipes, necessitate union nuts which must be driven to rotate around each pipe end and a mating end of each external piping. This is an intricate operation and needs much labor.
On the other hand, a blockish joint of the flange type for connection of the inlet and outlet pipes to the heat exchanger has been proposed in the U.S. Pat. No. 4,957,158 issued on Sep. 18, 1990. According to this proposal, two blockish joints are employed and one of them is attached to an upper end of the left-hand header, with another joint being attached to a lower end of the right-hand header. Each such joint comprises an inlet or outlet port for the heat exchanging medium, so that any intermediate short pipes are not necessary for the external pipings to be connected to the joints.
This proposal is advantageous in that any excessively large space is no longer required to the automobile body or the like, in contrast with the case wherein those pipes are directly connected to a heat exchanger body. Consequently, not only an effective area thereof can be increased, but also external pipings can be connected easily and in an efficient manner for example by fastening bolts or the like members.
It however has been observed that a considerable number of parts are undesirably needed to employ the system in accordance with that proposal. The operation for connection of one external piping to the inlet has to be done at a region different from that at which connection of the other piping is made to the outlet, thus causing much and intricate labor.